Prefix for "focus" or "pilot" (4)
I believe the answer is:
auto
I believe this clue is a double definition.
'prefix for focus' is the first definition.
(I've seen this in another clue)
'pilot' is the second definition.
(thesaurus)
(Other definitions for auto that I've seen before include "Lincoln?" , "Car (mostly US)" , "American vehicle" , "Prefix to denote self or same" , "Motor vehicle, in short" .)